,BIOL 271 Module 5 Exam | Microbiology
w/Lab Q&A | Portage Learning
1. The term that describes the ability of a microorganism to cause disease is:
A) Virulence
B) Pathogenicity
C) Infection
D) Disease
Correct Answer: B) Pathogenicity
Rationale: Pathogenicity is the qualitative ability of an organism to cause
disease. Virulence is the degree of pathogenicity. Infection refers to the invasion
of the host; disease is the clinical manifestation.
2. The degree of severity of disease caused by a pathogen is termed:
A) Infection
B) Virulence
C) Disease
D) Pathogenicity
Correct Answer: B) Virulence
Rationale: Virulence measures the severity or harmfulness of a disease. For
example, a highly virulent strain causes severe illness. Pathogenicity is the
ability to cause disease, not its severity.
,3. Which of the following is NOT one of the five steps of the infection process?
A) Entry
B) Attachment
C) Transformation
D) Evasion
Correct Answer: C) Transformation
Rationale: The five steps are entry, attachment, invasion, evasion, and
exit/transmission. Transformation is a genetic process in bacteria, not a step in
the infection cycle.
4. The portal of entry for pathogens that involves direct penetration through the
skin (e.g., needles, bites) is:
A) Mucous membranes
B) Parenteral route
C) Respiratory tract
D) Gastrointestinal tract
Correct Answer: B) Parenteral route
Rationale: Parenteral entry bypasses the skin or mucous membranes via
punctures, cuts, or injections. This contrasts with natural portals like the
respiratory or GI tracts.
, 5. A pathogen that attaches to host cells uses which type of virulence factor?
A) Toxins
B) Adhesins
C) Capsules
D) Flagella
Correct Answer: B) Adhesins
Rationale: Adhesins are surface molecules (e.g., pili, fimbriae) that bind to
specific receptors on host cells, enabling colonization and resisting removal.
Toxins damage cells; capsules evade phagocytosis.
6. The process by which a pathogen avoids destruction by the host’s immune
system is called:
A) Immune evasion
B) Phagocytosis
C) Inflammation
D) Opsonization
Correct Answer: A) Immune evasion
Rationale: Immune evasion strategies include hiding within cells, antigen
mimicry, antigen variation, and inhibiting phagocytosis. Phagocytosis and
inflammation are host defenses; opsonization enhances phagocytosis.
w/Lab Q&A | Portage Learning
1. The term that describes the ability of a microorganism to cause disease is:
A) Virulence
B) Pathogenicity
C) Infection
D) Disease
Correct Answer: B) Pathogenicity
Rationale: Pathogenicity is the qualitative ability of an organism to cause
disease. Virulence is the degree of pathogenicity. Infection refers to the invasion
of the host; disease is the clinical manifestation.
2. The degree of severity of disease caused by a pathogen is termed:
A) Infection
B) Virulence
C) Disease
D) Pathogenicity
Correct Answer: B) Virulence
Rationale: Virulence measures the severity or harmfulness of a disease. For
example, a highly virulent strain causes severe illness. Pathogenicity is the
ability to cause disease, not its severity.
,3. Which of the following is NOT one of the five steps of the infection process?
A) Entry
B) Attachment
C) Transformation
D) Evasion
Correct Answer: C) Transformation
Rationale: The five steps are entry, attachment, invasion, evasion, and
exit/transmission. Transformation is a genetic process in bacteria, not a step in
the infection cycle.
4. The portal of entry for pathogens that involves direct penetration through the
skin (e.g., needles, bites) is:
A) Mucous membranes
B) Parenteral route
C) Respiratory tract
D) Gastrointestinal tract
Correct Answer: B) Parenteral route
Rationale: Parenteral entry bypasses the skin or mucous membranes via
punctures, cuts, or injections. This contrasts with natural portals like the
respiratory or GI tracts.
, 5. A pathogen that attaches to host cells uses which type of virulence factor?
A) Toxins
B) Adhesins
C) Capsules
D) Flagella
Correct Answer: B) Adhesins
Rationale: Adhesins are surface molecules (e.g., pili, fimbriae) that bind to
specific receptors on host cells, enabling colonization and resisting removal.
Toxins damage cells; capsules evade phagocytosis.
6. The process by which a pathogen avoids destruction by the host’s immune
system is called:
A) Immune evasion
B) Phagocytosis
C) Inflammation
D) Opsonization
Correct Answer: A) Immune evasion
Rationale: Immune evasion strategies include hiding within cells, antigen
mimicry, antigen variation, and inhibiting phagocytosis. Phagocytosis and
inflammation are host defenses; opsonization enhances phagocytosis.
